The ‘Dirty’ Half Dozen: 6 Ingredients to Avoid for Stress-Free Skin Care

By Staff 14 Min Read

What we put in our bodies—food—is regulated by the Food and Drug Administration and the U.S. Department of Agriculture.

What we put on it—skin care and beauty products—is not.

That could be an issue.

In one 2021 report, scientists tested 231 popular makeup products from the U.S. and Canada and found that more than 100 had Per-and poly-fluoroalkyl substances (PFAS). These are chemicals that don’t break down and build up in the body over time.

They include perfluorooctanoic acid, which may cause cancer, according to the American Cancer Society.

Clean skin goes beyond washing your face.

“Your skin is a living, dynamic organ,” says Nava Greenfield, M.D. of Schweiger Dermatology Group in New York City. “Just like you consider carefully what you put into your mouth, you should take care in what you place on your skin.”

Understanding what’s in your products can help you achieve long-term health that’s more than skin-deep.

Here’s what the science says you should avoid—and what to use instead.

The skin is our largest organ, notes Marianna Blyumin-Karasik, board-certified dermatologist, co-founder of Precision Skin Institute, and founder of Stamina Cosmetics.

The skin has high absorption, “so skin care products that can be absorbed and enter our bloodstream can have detrimental effects on our overall health,” Blyumin-Karasik says.

Some ingredients like synthetic or highly concentrated fragrances or chemicals in personal care products can trigger skin sensitivity, irritation, or a more intense allergy.

Symptoms can include:

  • redness
  • itching
  • stinging
  • burning
  • bumps
  • scaling
  • roughness
  • blisters

Other ingredients have been linked to more serious problems, like:

  • cancer
  • cardiovascular disease
  • developmental issues
  • hormone disruption

For example, a 2018 review suggested that phthalates found in certain personal care products could adversely affect male fertility.

A 2021 study indicated that exposure to formaldehyde, sometimes used in keratin hair treatments, could lead to heart malformations in a developing fetus.

In 2020, California became the first state to issue a statewide ban on 24 chemicals, including methylene glycol and formaldehyde.

Other states don’t have these bans, leaving consumers to analyze and interpret labels themselves.

Complicating things, some recommendations to avoid specific ingredients aren’t one-size-fits-all. Different people may have different (or no) reactions to certain ingredients, even if they’re common allergens.

“Aside from real toxins and dangerous chemicals, a list like this will be different for each person,” Greenfield says. “Unfortunately, it’s not all black and white.”

Having an idea of what’s potentially toxic and what’s more likely to cause skin irritation can help you make informed decisions about the products you choose.

From common allergens to potential carcinogens, here are the ingredients Blyumin-Karasik and Greenfield suggest avoiding:

PEGs (polyethylene glycols)

Blyumin-Karasik and Greenfield warn that PEGs are a potential skin irritant.

They’re most often found in lotions, creams, and hair products because they can act as skin conditioners and humectants, a common moisturizing agent.

A small 2021 case study examined six cases of acute sensitivity to PEGs. However, researchers also noted the allergy was rare.

Methyl and propyl parabens

Blyumin-Karasik notes that methyl and propyl parabens are preservatives with reputations for being hormone disruptors. However, research is mixed.

A 2017 study on gerbil prostates indicated that methylparaben could disrupt estrogenic and androgenic receptors that might affect the prostate.

Another 2017 study suggested parabens, including methyl and propyl parabens, posed little health risk. However, researchers noted that parabens could inhibit compounds with anti-estrogenic properties.

The FDA wrote in 2022 that it didn’t have enough evidence to warn that parabens affect human health. The American Academy of Dermatology (AAD) reported similarly in 2019, noting that allergic reaction risks were low.


Found in some eye make-up products, lipsticks, and deodorants, aluminum can cause skin irritation, according to Greenfield.

There’s also been discussion as to whether aluminum is a carcinogen, or cancer-causing agent.

A 2015 study suggested aluminum can increase the migration of breast cancer cells and called for more research.

In 2013, the Cosmetic Ingredient Review said alumina and aluminum hydroxide was safe to put in cosmetics, noting that it doesn’t get absorbed into the skin and less than 1 percent is absorbed orally.


This ingredient is a preservative commonly found in soaps and shampoos and may cause skin irritation or allergies, Blyumin-Karasik explains. Greenfield agrees with avoiding formaldehyde, saying it’s a common irritant.

A 13-year retrospective study of patch tests published in 2020 indicated that a polymer known as toluene-sulfonamide-formaldehyde resin (R-TSF or TSFR), often used in nail polish, was one of the most common allergens. It’s also known as a carcinogen, but data shows it’s only hazardous if a person inhales a significant amount.

The American Cancer Society says formaldehyde in personal care products like shampoos typically contains formaldehyde levels that are “far below hazardous” to health. The organization says keratin hair smoothing treatments can raise indoor air concentration to hazardous levels.


Phthalates are typically used to make sure plastic doesn’t break. They can also be used in fragrances in skin products. Blyumin-Karasik warns they may disrupt hormones.

A 2020 literature review indicated that phthalates could lead to:

  • altered puberty
  • testicular dysgenesis syndrome, a condition affecting semen quality and testicle descent
  • increase risk for cancer
  • increase risk of male and female fertility issues
  • modify the release of hypothalamic, pituitary, and peripheral hormones

A 2018 study suggested phthalates could lead to pregnancy loss and fertility issues.

However, it’s important to note that neither piece of research above was specific to phthalates in beauty products.


Key West and Hawaii recently banned oxybenozone, which is commonly found in sunscreen. Blyumin-Karasik says it can disrupt hormones and cause allergic reactions.

A 2020 review of 29 studies indicated no a link between fertility issues and oxybenzone and called for more research.

However, an older 2016 study indicated that men with higher levels of benzophenone-type ultraviolet (UV) filter concentrations had lower sperm concentrations.

Avoiding fragranced products and using a mineral-based sunscreen can help avoid harmful chemicals, Blyumin-Karasik says. Looking for preservative-free items can also cut down on risks of irritants and health hazards.

“The main purpose of preservatives is to maintain the integrity of the personal care products,” Blyumin-Karasik says. “The natural alternatives may not attain as long of the shelf-life as the chemical ones, but they’re better for our well-being.”

To clean up your beauty regimen, Blyumin-Karasik suggests looking for products that contain these safer ingredients instead.

Tea tree oil

Blyumin-Karasik suggests using tea tree oil, an essential oil found in shampoos, skin care items, hand sanitizers, and first aid products.

A 2021 study suggested tea tree oil could help disinfect hands when used in sanitizer.

Research from 2015 indicated it could aid wound healing, and a 12-week pilot study published in 2017 suggested it could reduce acne.


Instead of PEGs, opt for a humectant with fewer potential side effects. Blyumin-Karasik recommends glycerin.

One small 2017 study of women indicated that products with a mix of hyaluronic acid, glycerin, and Centella asiatica (gotu kola) could boost skin hydration for 24 hours.

A 2019 safety assessment suggested glycerin was safe to use in cosmetic practices.

Coconut oil

Coconut oil, or Cocus nucifera, is extracted from the meaty part of a coconut fruit.

Blyumin-Karasik recommends it because it’s moisturizing and can reduce mold growth in skin care products.

A 2022 study indicated that a coconut oil-based serum combined with deer antler stem cell extract for two weeks could:

  • smooth skin
  • reduce the appearance of fine lines and wrinkles
  • increase collagen density
  • moisturize

A 2019 study indicated virgin coconut oil had anti-inflammatory properties and supported its use in skin care products.

Elderberry extract

Blyumin-Karasik says elderberry, or Sambucus nigra extract, often found in serums, has “versatile benefits for our skin.”

She notes these benefits include antimicrobial effects and high levels of vitamin C.

Research on elderberry is limited, particularly in topical products. However, a 2019 study suggested it had anti-aging benefits when ingested as a supplement.

Willow bark extract

Blyumin-Karasik says willow bark, or Salix nigra extract, is an excellent source of skin preservation. She recommends it for its anti-inflammatory and antimicrobial properties.

“Besides that, willow bark contains a potent salicin ingredient which has gentle exfoliating properties to cleanse pores and reduce skin surface oil,” she says.

A 2019 study suggested willow bark total extract may have antioxidant and anti-inflammatory benefits.

An older 2010 study suggested that salicin, which is extracted from white willow bark, may have benefits when applied to the skin topically.

When shopping for personal care products, there are a few things you’ll want to keep in mind, depending on your age and any conditions you have.

Layering is not for skin care

Leave the layering for sweater weather, not skin care. Blyumin-Karasik says the biggest issues she sees in her clinic happen when people try to cake on too many products or ingredients.

“Trying to be innovative or frugal, young individuals play with potentially hazardous ingredients such as baking soda or lemon juice which can lead to significant skin irritation,” Blyumin-Karasik says. “Older individuals try to layer too many products onto their skin such alpha hydroxy acids and potent retinoids and as a result, create skin allergy or irritation.”

Blyumin-Karasik recommends working with a dermatologist to find the correct ingredients for your skin type and beauty goals.

More is not always more

A long ingredients list doesn’t necessarily mean there are a ton of items working to boost your skin’s health. Sometimes, simple ingredient lists are most effective.

“In general, if a skin care product has too many chemicals or fragrances, it can irritate the skin and cause skin rashes, and it’s best to avoid,” Blyumin-Karasik says.

Sensitive skin, eczema, dermatitis, or rosacea

Individuals with sensitive skin, eczema, dermatitis, or rosacea will want to pay particular attention to product labels and the “less is more” mantra, Blyumin-Karasik says, as people with these conditions are more prone to irritation.

“They’re best served by using fragrance-free, sensitive skincare lines such as Avene and Bioderma, and definitely avoiding any of the above skin allergens,” Blyumin-Karasik says.


Blyumin-Karasik advises acne-prone individuals to opt for products that won’t clog pores. She suggests looking for words like “oil-free” and “noncomedogenic” and minimizing the use of occlusive moisturizers or make-up.

These “can cause more breakouts and blemishes,” Blyumin-Karasik warns.

When purchasing skin care products, you’re making an investment in your body’s largest organ.

But some ingredients may not serve your skin — or overall health.

Though research in some cases is minimal and others are mixed, Phthalates and some parabens are linked to hormonal disruption. Other ingredients are carcinogens or may cause irritation.

Speaking with a dermatologist can help you figure out the best and safest products and ingredients for your skin and overall health.

Beth Ann Mayer is a New York-based freelance writer and content strategist who specializes in health and parenting writing. Her work has been published in Parents, Shape, and Inside Lacrosse. She is a co-founder of digital content agency Lemonseed Creative and is a graduate of Syracuse University. You can connect with her on LinkedIn.

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